1. Field of the Invention
The present invention relates to filters. More particularly, the present invention relates to filter assemblies for filtering particulates from a fluid. Most particularly, the present invention relates to a conical fluid filter cartridge and a method of sealingly mounting such filter cartridge in a conical filter housing and/or support and/or cage of a diameter the same as, or slightly larger than, the diameter of the conical filter cartridge.
2. Description of the Prior Art
The need to filter a wide variety of fluids to remove solids of almost any size and composition is widely known. A device widely used for filtering, for example, particulates from a liquid, is a single stage filter bag within a perforated basket or core. However, also widely known in the art is the fact that such bag filters have a relatively short life, and have a tendency to unload or blow the contaminant right through the filter basket if the pressure differential gets too high. Also, for their volumetric size, bag filters do not provide much surface area or dirt holding capacity in relation to their diameter. Thus, those skilled in the art sought a solution as to how to provide a more efficient, and less costly, method of removing solids from a wide variety of fluids.
Applicant's assignee, in an attempt to solve the problems with bag filters, developed a pleated coreless, cylindrical filter element. It was found that either one large, or three smaller diameter coreless filters and support cages could be placed in the space formerly occupied by a single bag filter and give a large increase in surface area. However, an unanticipated problem arose. While a bag filter is flexible, a pleated coreless filter is much less flexible. Since the bag filter and the coreless filter both flow inside to outside, as the particles were being removed from the fluid, they would form a filter cake on the inside of the filter media. The filter media was pressed into the retaining cage and its openings, and removing the filter by pulling straight up was difficult. While the bag filter was flexible, and a mere shaking of the filter would cause the cake to fall off the sides of the bag where it could easily be removed from the filter, this did not happen with the cylindrical coreless filters. Not only does the filter media extrude into the perforations of the retaining cage, in some cases the elements fill up completely with solids, forming a solid tube, making removal extremely difficult. This problem was further exacerbated when, under certain change out procedures such as steaming or drying filters prior to change out, the filter cake became almost cement-like, providing even more rigidity to the media. Therefore, there continued to be a search for a solution as to how to provide a greater filtration area than a bag filter, but without the filter element removal problems of the coreless pleated filter.